Heating furnace



J. H. KNAPP HEATING FURNACE Filed Nov. 27 f 1923 3 Sheets-Sheet 1 INVENTOR am, .21 i924 J. H. KNAPP HEATING FURNACE 27 1923 5 Sheets-Sheet. 2

Filed Nov.

, ma amva INVENTOR J. H. KNAPP HEATING FURNACE 3 Sheets-Shee t. '5

Filed Nov. 27. 1923 R 0 T N E v m i To all whom it may concern:

Patented oee 21, .1924.

Be it known thatI, JAMES H. KNAPP, a

"citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State" of California, have invented a new and useful Improvement 'in Heating Furnaces, of whichthe following is afull, clear, and exact description.

Thet-present invention relates to heating furnaces employed for the heat treatment of metal or other materiahand more particularly to heating furnaces of the car type.

In heating furnaces, particularly in heating furnaces of the car type, the difficulty is generally encountered of. a cold due to the fact that thetop of the heating chamber of such a. furnace is heated not only directly by the hot gases of combustion sweeping from the top'of the bridge wall,

but-also by radiation over the roof of the chamber, whereas the bottom of the -chambar depends for its heat-primarily upon the gases owing therethrough which have already given up alarge portion of their heat in passing through the upper portiomof the chamber. Furthermore, in the operation of a heating furnace of the car type the movable bottom when taken out of the furnace cools off, so that when it is replaced in the furnace it is relatively cool as compared' with the side walls and roof of the heating; chamber, which adds to the difiiculty oi rapidly warming up the lower portion of the heating chamber.

By the present invention I propose to overcome the above difii'cult-y in a heating" furnace by the provision inthe lower portion of the hrid e wall thereof of relatively thin shields of neat-resisting and heat-comducting material the function of which is to quickly transmit heat from the combustion chamber to therbottom and lower portion of the heating chamber of the furnace.

In the accompanying drawings, there is shown, for purposes of illustration only, one

embodiment of the present invention, it "being understood that the drawings do not define the limits of the invention, as changes may be made in the construction and operation therein' dis'closed without departing from the spirit of the invention or scope of my'broa der claims.

In the drawings- Figure 1 is a vertical transverse s 'ctional view of a heating furnace of the 1- type embodying my invention, the said by the upper Application filled-November 27, 1923. Serial 80. 877,215.

thereof only; Figure 2 is a vertical" 1o tional view onthe line II- of Figure 1; Figure 3 is a f entary sectional view on the line IIL-II ofFigure 1;

Figure 4 is.afragmentary sectional view on the line IV-'I V of Figure 2 Figure 5 is a vertical transverse sectional having combustion chambers at one side 'tudinal secview of a furnace of the-car t combustion chambers on OPPOSIDSldBS o the heatingchamber; and i section being plartly in the plane'ie' resented 0 Figure 5 and artly in theplane represented by the lower' oriZontal-portion of said line. b

Referring to the-embodiment of the in- F gure 6 's-a. sectional view through one" side of the furnace shown in- Figure 5, the

orizontal portion 0 the line vention-illustrated in Figuresl to 4, inclusive, the reference numeral 2 indicates a furnace of the car type having a heating chamber 3" the-bhargmg opening 4; of which is closed. bya-door 5 adapted to be operated by any. suitable means,- The heating chamber is provided with'the usual movable bob tom 6 provided'with flanged wheels 'F'b'g which the said bottom is supported-ion movement upon tracks 8 where y th e'bots tom may be moved into and out of the jurnace.

= The furnace is providedat oneside thei'eof with combustion chambers 9 separated'from the heating chamber by a bridgemall 10. "The fuel, which maybe oil or gas, is introduced into the combustion chambers through burner openings 11. and the hot combustion gases pass from the combustion chambers over the top ofthe bridge wall into the top portion o f, the heating chamber; These gases flow downwardly through the heat;-

ing chamber and pass out of the furnace through outlet hearth level.

As already'pointed out, in a. furnaceof this type as ordinarily constructed-the top portion of the heating chamber warms'up much more rapidly than the bottom portion thereof, causing the difiiculty commonly referred to as cold bottom. V In order to overcome this defect, I provide openings 13 .in the lower portion of the bridge wall and close such openings by relatively thin shields- 14 of heat-resistin and heat-conducting ter e h sh e dsere prflfimbly m d ports 12 located near the as shown, ofsilicon carbide,-as this material is" highly: refractor and .is, therefore, ca-

' -pable of withstan ing high temperatures even when employed in relatively thin slabs.

However, my mvention is not limited to the use of this particular material, as a heat-resisting alloy or other suitable material may be employed if desired. -These shields are adapted to radiate heat directly onto the bottom ofthe heatingchamber, and being very thin in proportion to the thicknessof the bridge wall and of a high heat-conduct ing material, they become red hot and a radiating medium very soon after the furnace has been lighted. By reason of these shields in the lower portionoi thebridgewall, it is possible to warm up the bottom portion of -material.

on bo'thsi es of the heating chamber., Inthis construction-of furnace each bridge wall 15 is provided in'the lower portion thereof with openingslfifin'which are placed shields 17 of heat resisting and heatfconducting While I have" "illustrated my invention as.

embodied inheating furnaces oi the-car, type, it will be a parent that the inventionalso has utilitym connection with heating furnaces of-the solid hearth type, that is, furraces in which the hearth is stationary. The invention 'is, therefore, not limited tothe particular type of furnace nor to the details of construction. shown, as it may be others wiseembodied within the scope of the ap- ,pendedi'claims.

I claim: v L, A heating furnace comprising a heat- I ingtchamber, a combustion chamber, and abridge wall separating said chambers, said brid e wall having a relatively thin lower portion formed of heat-resisting and heatconducting material, substantially as described.

2. Av heating furnace comprising a'heatingchambei', a, combustion chamber, a bridge wall separating said chambers and havmg an'o ni in the lower portion thereof, and

a shield o heat-resisting and heat-conducting material closing said opening, substantia ly as described. 7

3. A heating furnace comprising a heating v chamber, a combustion chamber, a

' stantially as described.

- 9. A heating furnace comprising a heat- 100 ing chamber havinga'movab e bridge wall separating said chambers and having an opening in the lower portion thereof, and a'shield of heat-resisting and heat-conducting material of less thickness 60 than said brldge wallclosing said opening, 1

substantially as described. I 4. A heating furnace com rising a heat-4 mg chamber, a combustion c amber, anda wall interposed between said heating chamher and said combustion chamber, said wall having a relatively thin lower portion formed of heat-resi'stin and-heatrconducting material, substantia ly as described.

5. A heating furnace comprisinga bridge 7 I wall provided with openings in the lower portion thereof, and relatively thin shields of heat-resisting and heat-conducting material closing said openings, substantially as, described.

lug-chamber, a com'bustion'chamber, abridge wall separating said chambers and having an'openingin the lower portion thereof,

and a relatively thin shield of silicon carbide closing Lsaid opening, substantially as described.

7, A heating furnace comprising a heating' chamber, combustion chambers atopposite sides of said heating chamber, bridge 35 walls separating said heating chamber from. said combustion chambers and each having V an opening in the low'er portion thereof, and relatively thin shields of heat-resisting and'heabconducting material closing sai openings, substantially as described.

8. A heating furnace comprising a heating chamber iaving amovable-bottom, a

'combustion chamber, a bridge wall separating said chambers and havmg an opening in the lower portion thereof, and a relatively thin shield of heat-resisting and heat-conducting material closing said opening, subbottom, com} bustion chambers at opposite sides of said heating chamber, bridge walls separating said heating chamber from said combustion chambers-and-each having an opening in 0 the lower portion thereof and relatively thin shields of heat-resisting and heat-conducting material closing saidopenings, substantially as described.

In testimony whereof Ihave hereunto set in hand.

' JAMES H. KNAPP.

. .75 6. Ahe'ating furnace comprising a heat- 

